Apparatus for measuring moisture



March 3l, 1953 R. L. MolLvAlNE APPARATUS RoR MEAsuRING MOISTURE 2 SHEETS-SHEET l Filed June l1, 1948 March 31, T953 R, MclLvAlNr-z 2,633,018

APPARATUS FORMEASURIING MOISTURE me@ June 11, 194s 2 SHEETS-.SHEET 2 Patented Mar. 31, 1953 2,633,018 APPARATUS FOR MEASURING MOISTURE Robert L. Mcllvaine, Glencoe, Ill., assigner, by

mesne assignments, to Herbert Simpson Corporation, Chicago, Ill., a corporation of Illinois Application June 11, 1948, Serial No. 32,407

(Cl. 'I3-76) 1 Claim.

This invention relates to a novel means for determining the amount of moisture in a given material. More particularly this invention has to do with apparatus for measuring the percent of moisture in a quantity of sand or the like by evaporating the moisture from the sand and recording the decrease in weight as the moisture is evaporated.

In preparing a mold, it is necessary to add Water to the sand to give it the required molding characteristics. Sand that does not have enough moisture tends to crumble while sand that is too wet causes the formation of cavities that effect the soundness of the casting and may possibly cause the mold to explode.

In any foundry, therefore, there is need for a device by which the percent of moisture in a batch of sand can be quickly and accurately determined. This device should preferably be small and compact since space in a foundry is at a premium.

Since foundry sand is mixed in large batches, it is evident that the amount of moisture in the entire batch cannot be measured directly in any efficient manner. However, since the sand is thoroughly mixed before it is ready for use, a representative small sample of the sand may be used in carrying out a moisture determination and the results sol obtained will be an accurate indication of the amount of moisture in the total batch.

It is, therefore, an object of this invention to provide means for quickly and accurately determining the moisture content of foundry molding sand or other material of similar nature.

Another object of this invention is to provide a small, portable apparatus that is adapted to accurately measure the amount of moisture in a small, representative sample of the batch of sand being processed.

According to the general features of this invention there is provided a small sensitive scale having a shallow container on the platform of the scale adapted to receive 10 grams of sand. The dial of the scale may be conveniently divided into ten major portions with each portion divided into ten subdivisions and so related to the scale mechanism that the indicating hand will read 10 grams when the pan is empty and will read zero when the pan contains l grams of the sand. A heating means is positioned adjacent the sand in the scale pan which is operative for quickly bringing the temperature of the sample to the evaporating temperature of the moisture in the sand whereby the moisture will be driven ofi and the percent moisture in the sample will be recorded on the scale by the movement of the indicating hand away from the zero point,

A feature of this invention is the provision of a heating means which may be quickly adjusted relative to the sample.

Another feature of this invention is the provision of means for magnifying the dial on the scale for facilitating accurate reading thereof.

Other and further features, objects and advantages of the present invention will be apparent to those skilled in the art from the following detailed description taken in connection with the annexed sheet of drawings.

Figure 1 is a front elevational view of the heating means and the scale means of the present invention assembled on a support platform.

Figure 2 is a fragmentary front elevational view of a modified form of the scale which is adapted to be used in the present invention.

Figure 3 is a sectional view taken on line III- III of Figure 2 looking in the direction indicated by the arrows.

Figure 4 is a fragmentary front elevational view of a modified form of the scale of this invention.

Figure 5 is a front elevational view of a modified scale constructed according to the teachings of the present invention.

Figure 6 is a front elevational View of another modified form of scale of this invention.

As shown on the drawings:

In Figure l, the reference numeral I0 indicates generally a base structure on which is disposed a scale II and an upright support rod I2 secured by anv suitable means in said base. A heating element I3 is supported substantially over the scale I I at the end of a rod I5 which has a collar portion I6 disposed around the rod. An adjustment collar I'I is secured to the rod I2 by a set screw I8 and is effective to regulate the height of the heating element relative to the scale and to the base structure.

The heating element may be any suitable type which emits a considerable amount of radiant heat such as an electric heating unit or a piece of metal previously heated to a red heat by means of a gas ame or other heating means.

The scale II may be of any commercial type that is small and has a sensitive mechanism such as a postal scale with a dial I9 having a full scale reading of approximately 10 grams, each gram divided into 10 subdivisions. As will be noted in Figure 1 the plunger 2D of the scale moves downwardly under load and therefore the indicating arm 2| will read 10 grams when the scale is unloaded and will read zero grams when the scale has 10 grams disposed thereon.

On top of the scale platform 22 there is provided an insulating pad 23 of any suitable material, such as asbestos. A light, shallow container 2d is removably disposed on the pad 23. To measure the percent of moisture in a batch of sand, a representative sample of the sand is lightly placed in the shallow container 24 on the scale in increasing amounts until the indicating hand 2l reaches the zero reading. It will be understood, of course, ,that the scale has been previously adjusted to read grams With the pad 23 and the container 2d on the platform of the scale.

The heating element is then swung into position directly over thev material in the container and the material is very quickly heated to above 212 by radiation and convection with the result that the material is dried within a very few seconds thus lightening the load on the scale. The indicating hand will, therefore, move down in the scale from the full load zero position to a position which indicates the percent ci moisture that was in the sample on the scale container. Thus, if the indicating hand stopped at the one gram reading it would indicate that a tenth of the total weight of the sample has been removed from the scale and therefore the sample ccntained 10% moisture. Since the scale is divided into 100 divisions the readings will give a direct reading of percentage.

Figure 2 illustrates a modiiied form of the apparatus of this invention. Since the scale has been divided into A100 divisions and each din vision therefore indicates one percent moisture in the sand, it might be difficult to accurately estimate the reading between adjacent one percent graduations. In this modication therefore there is provided a sliding scale 2S, as shown in Figure 3, having llange members 29 arranged to hook around the edges 39 of the dial i9 of the scale ll. The sliding scale 2t may therefore be slid along the marginal edge of the dial portion of the scale. The scale 23 is substantially longer than the distance between one division on the large dial of the scale i l and has a portion calibrated from zero to l0 which is exactly equal to the distance between one gram divisions as for instance between Zero and l, as indicated at Figure 2. Referring to Figure 2, after the in dicating arm 2! stops after the evaporation of the moisture of the sample, Aas indicated in this ngure, the sliding scale 28 is moved along the outer marginal edge of the main dial l 9 until the zero of the scale 28 is directly opposite the in dicating hand.

A magnifying glass 32, carried on a lJ-shaped frame t3, has a rear flange portion 34 hooked over and secured to the upper edge of the sliding scale 253 and a forward lange portion 35 overhanging the dial portion of the Sliding scale 2S with the upper edge of the indicating arm 2l between the glass and the scale 28. This magnifying glass 32 is held on the frame 3.3 by tabs 35 bent out from the frame for engaging over the glass. A cutout portion 3l on the forward flange se permits the dial of the scale 28 to be read through the magnifying glass.

In Figure 2 the reading indicated thereon is 25%. The use of a sliding scale which is divided into one-tenth gram division obviates the necessity of Calibrating the entire main dial ld of the scale and also the magnifying glass 32 permits a more accurate reading of the Lone-tenth divisional mark.

In Figure 4 a further modication of the scale of this invention is illustrated. In this form the sliding magnifying glass 32 of Figure 2 is attached to a scale lill which has a one gram division calibrated in 146 gram subdivisions. In operation, if the operator, through inadvertence or due to the texture of the wet sand, fails to bring the indicator arm 2l exactly up to the zero mark on the xed scale B9, the magnified sliding scale 40 is moved before the heating of the sand is begun to a point where the zero of scale 40 is aligned with the indicator arm 2l.

By use of this sliding scale 40 the percent of error in any moisture determination can be greatly reduced. For example, supposing, by mistake, only 9.5 grams of certain moisture content is put .on the pan of the scale instead of the 10 grams required to bring the indicator arm to zero. The arm will then indicate 0.5 of a grani and, if evaporation is begun then, the iinal moisture content reading will have a 5% error due to the initial 5% reading, However, if the sliding scale el) is used and the zero of the scale is aligned With the indicating Aarrn before the evaporation of moisture is begun, the scale will record the .actual percent of moisture evaporation. The error due to the 9.5 gram load will then be reilected, not directly in percent of moisture, but in the same ratio as total weight of sand to reduction kin Weight.

A still further modification .of the scale of this invention may be so adjusted that in reality the range of the indicating hand would be only one gram for the entire scale. This would mean that as the ten grams of sand were placed on the scale, the hand would remain olf the dial until nine grams had been added and would only move over the surface of the dial between the ninth and tenth gram, coming to rest at zero when exactly ten grams had been placed in the con tainer, This, each main divisional mark on the main dial of the scale would record one-tenth of a gram, Thus, the percentage of moisture could be measured accurately to much less than one percent.

This type of scale could be effected in many ways as by displacing the plunger 2li, Fig. 5, away from the lower pivoted end of the indicating hand 2 l of the scale I I' so that upon sand being deposited in the pan on top of the scale the plunger would move down against the action of a calibrated spring 43 until at exactly nine grams it would come in contact with the end of the indicating arm and would from there on indicate the Weight of the last gram of material placed on the pan. Or, in another embodiment shown in Figure 6 a nine-gram Weight 45 could be balanced on the beam 2| of the scale Il" so that the plunger 2D moving downward under the load would have to take up this nine-gram weight first before it could indicate the last gram.

If the sliding scale 28 were incorporated in such a device the dial could be read to one-tenth of one percent of moisture in the sand.

From the foregoing disclosure it is evident that there is provided in this invention a very simple means for accurately measuring the amount of moisture in a sample of sand or the like. All that is required in this mechanism is a sensitive small scale and a source of heat that may be positioned over the contents in the pan of the scale. It is evident that this apparatus is compact and could readily be set up in a foundry in any convenient corner without interfering with the normal operations on the foundry floor.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon otherwise than necessitated by the scope of the appended claim.

I claim:

In a device for measuring moisture content of a wet ungible mass, the combination comprising: a scale including a dial having graduations, va balance beam having an indicating pointer movable over said dial, a vertically reciprocable plunger operatively connected to said beam to deiiect said pointer across said dial by a downward movement, and a platform carried atop said plunger; a shallow sample dish removably disposed on said platform and opening upwardly to receive radiant heat from above, a heat -insulating pad interposed between said platform and said dish to prevent heat transfer to said scale, and a weight on said beam positioned to counterbalance a predetermined proportion of the mass in said sample dish which is required to deflect said indicating pointer fully across said dial, said dial graduations including a zero mark at the full scale deection of said pointer and successively increasing values marked across said dial corresponding to the weight of the removed moisture.

ROBERT L. MCILVAINE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,356,287 Jaenichen Oct. 19, 1920 1,505,343 Heath Aug. 19, 1924 1,757,766 Ferguson et al May 6, 1930 1,959,832 Lesh May 22, 1934 2,117,441 McWeeny May 17, 1938 FOREIGN PATENTS Number Country Date 16,681 Great Britain 1913 266,628 Great Britain Mar. 3, 1927 321,243 Germany May 27, 1920 468,100 Great Britain June 29, 1937 700,167 France Feb. 22, 1930 

